In recent years, for example, a network technology called content centric networking (CCN) has been known for distributing contents such as videos and audios. CCN is also called, for example, information centric networking (ICN) or named data networking (NDN). CCN allows a user to acquire desired contents by using a contents name indicating the desired contents as a key without being conscious of the location of a server in which the desired contents are stored.
A user terminal transfers an Interest packet including the content name indicating the desired contents to the server via a relay node in a network. The relay node relays the Interest packet by Hop-by-Hop communication. Then, when the Interest packet is received, the server acquires the contents corresponding to the contents name in the Interest packet from a storage destination. The server transfers the contents to each relay node on a path through which the Interest packet is transferred. When the contents are received, each relay node stores the received contents in a cache. Then, the relay node transfers the contents stored in the cache to the user terminal.
Related technologies are disclosed in, for example, Japanese Laid-Open Patent Publication No. 2013-179482 and Japanese Laid-Open Patent Publication No. 2015-136098.